A breeding program was initiated during the late 90's near Bakersfield in San Joaquin Valley of Central California. In 2004, during this breeding program, a new variety of Vitis vinifera was created by deliberate cross breeding of two parent plants by emasculation of the pollen bearing organ of the female and introducing pollen from another male origin. The female parent of the new variety was GSB5, a medium-sized black almost seedless grape variety with a fleshy texture and a natural flavor (non-patented in the United States). The male parent (i.e. the pollen parent) of the new variety was GRW3, a vigorous black variety with a crisp texture and a natural flavor (non-patented in the United States).
TABLE 1Comparison of ARRATWENTYFOUR with its parentsand the closest related variety:ARRA-Summer RoyalTWENTY-(ComparisonFOURGSB5GRW3Variety)BerryMediumGoodVery GoodGoodattachmentBerry size20-2220-2218-2218-20Bunches3232-363242per vineBunchSemi tightTightMediumSlightly looseDensity
The parentage of the new variety can be summarized as follows:GSB5 X GRW3
An artificial pollination was created, and the result was an embryo which possessed unique genetic qualities. The rudiments resulting from the above pollination were embryo rescued.
In 2006 the plant was transplanted to Bakersfield in San Joaquin Valley of Central California.
It was found that the new grapevine of the present invention possesses the following combination of characteristics:                (a) Forms attractive moderately firm seedless berries with a purple-black skin coloration; in semi-tight clusters which display a naturally sweet flavor,        (b) Commonly bears fruit during the month of June in the San Joaquin Valley of Central California, U.S.A., and        (c) Bears fruit that is moderately firm and is amenable for storage, handling, and shipping.        
The new variety during observation to date has displayed no visible disease, and has displayed an ability to well resist cold, drought, heat; but sensitive to direct exposure to sun and wind. The fruit of the new variety has been found to display qualities suitable for handling and shipping combined with desirable dessert eating qualities.
The new variety of the present invention has been found to undergo asexual propagation beginning in 2006 near Bakersfield in the San Joaquin Valley of Central California, U.S.A. by bud grafting on mature Thompson rootstock (non-patented in the United States). Such asexual propagation was conducted successively from 2006 until 2007 for a total of two growing seasons, and has shown that the characteristics of the new variety are strictly transmissible from one generation to another. Accordingly, the new variety undergoes asexual propagation in a true to type manner.